Abstract
Recently, we identified dysadherin, a novel carcinoma-associated glycoprotein, and showed that overexpression of dysadherin in human hepatocarcinoma, PLC/PRF/5 cells could suppress E-cadherin-mediated cell-cell adhesion and promote tumor metastasis. The present study shows evidence that dysadherin is actually O-glycosylated. This was based on a direct carbohydrate composition analysis of a chimera protein of an extracellular domain of dysadherin fused to an Fc fragment of immunoglobulin. To assess the importance of O-glycosylation in dysadherin function, dysadherin-transfected hepatocarcinoma cells were cultured in a medium containing benzyl-α-GalNAc, a modulator of O-glycosylation. This treatment facilitated homotypic cell adhesion among dysadherin transfectants accompanied with morphological changes, indicating that the anti-adhesive effect of dysadherin was weakened. Modification of O-glycan synthesis also resulted in down-regulation of dysadherin expression and up-regulation of E-cadherin expression in dysadherin transfectants but did not affect E-cadherin expression in mock transfectants. Structural analysis of O-glycans released from the dysadherin chimera proteins indicated that a series of O-glycans with core 1 and 2 structures are attached to dysadherin, and their sialylation is remarkably inhibited by benzyl-α-GalNAc treatment. However, sialidase treatment of the cells did not affect calcium-dependent cell aggregation, which excluded the possibility that sialic acid itself is directly involved in cell-cell adhesion. We suggest that aberrant O-glycosylation in carcinoma cells inhibits stable expression of dysadherin and leads to the up-regulation of E-cadherin expression by an unknown mechanism, resulting in increased cell-cell adhesion. The carbohydrate-directed approach to the regulation of dysadherin expression might be a new strategy for cancer therapy.
| Original language | English |
|---|---|
| Pages (from-to) | 521-527 |
| Number of pages | 7 |
| Journal | Glycobiology |
| Volume | 13 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - 2003 Jul 1 |
| Externally published | Yes |
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Keywords
- Benzyl-α-Ga1NAc
- Cell-cell adhesion
- Dysadherin
- E-cadherin
- O-glycosylation
ASJC Scopus subject areas
- Biochemistry
Cite this
Aberrant O-glycosylation inhibits stable expression of dysadherin, a carcinoma-associated antigen, and facilities cell-cell adhesion. / Tsuji, Hitomi; Takasaki, Seiichi; Sakamoto, Michiie; Irimura, Tatsuro; Hirohashi, Setsuo.
In: Glycobiology, Vol. 13, No. 7, 01.07.2003, p. 521-527.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Aberrant O-glycosylation inhibits stable expression of dysadherin, a carcinoma-associated antigen, and facilities cell-cell adhesion
AU - Tsuji, Hitomi
AU - Takasaki, Seiichi
AU - Sakamoto, Michiie
AU - Irimura, Tatsuro
AU - Hirohashi, Setsuo
PY - 2003/7/1
Y1 - 2003/7/1
N2 - Recently, we identified dysadherin, a novel carcinoma-associated glycoprotein, and showed that overexpression of dysadherin in human hepatocarcinoma, PLC/PRF/5 cells could suppress E-cadherin-mediated cell-cell adhesion and promote tumor metastasis. The present study shows evidence that dysadherin is actually O-glycosylated. This was based on a direct carbohydrate composition analysis of a chimera protein of an extracellular domain of dysadherin fused to an Fc fragment of immunoglobulin. To assess the importance of O-glycosylation in dysadherin function, dysadherin-transfected hepatocarcinoma cells were cultured in a medium containing benzyl-α-GalNAc, a modulator of O-glycosylation. This treatment facilitated homotypic cell adhesion among dysadherin transfectants accompanied with morphological changes, indicating that the anti-adhesive effect of dysadherin was weakened. Modification of O-glycan synthesis also resulted in down-regulation of dysadherin expression and up-regulation of E-cadherin expression in dysadherin transfectants but did not affect E-cadherin expression in mock transfectants. Structural analysis of O-glycans released from the dysadherin chimera proteins indicated that a series of O-glycans with core 1 and 2 structures are attached to dysadherin, and their sialylation is remarkably inhibited by benzyl-α-GalNAc treatment. However, sialidase treatment of the cells did not affect calcium-dependent cell aggregation, which excluded the possibility that sialic acid itself is directly involved in cell-cell adhesion. We suggest that aberrant O-glycosylation in carcinoma cells inhibits stable expression of dysadherin and leads to the up-regulation of E-cadherin expression by an unknown mechanism, resulting in increased cell-cell adhesion. The carbohydrate-directed approach to the regulation of dysadherin expression might be a new strategy for cancer therapy.
AB - Recently, we identified dysadherin, a novel carcinoma-associated glycoprotein, and showed that overexpression of dysadherin in human hepatocarcinoma, PLC/PRF/5 cells could suppress E-cadherin-mediated cell-cell adhesion and promote tumor metastasis. The present study shows evidence that dysadherin is actually O-glycosylated. This was based on a direct carbohydrate composition analysis of a chimera protein of an extracellular domain of dysadherin fused to an Fc fragment of immunoglobulin. To assess the importance of O-glycosylation in dysadherin function, dysadherin-transfected hepatocarcinoma cells were cultured in a medium containing benzyl-α-GalNAc, a modulator of O-glycosylation. This treatment facilitated homotypic cell adhesion among dysadherin transfectants accompanied with morphological changes, indicating that the anti-adhesive effect of dysadherin was weakened. Modification of O-glycan synthesis also resulted in down-regulation of dysadherin expression and up-regulation of E-cadherin expression in dysadherin transfectants but did not affect E-cadherin expression in mock transfectants. Structural analysis of O-glycans released from the dysadherin chimera proteins indicated that a series of O-glycans with core 1 and 2 structures are attached to dysadherin, and their sialylation is remarkably inhibited by benzyl-α-GalNAc treatment. However, sialidase treatment of the cells did not affect calcium-dependent cell aggregation, which excluded the possibility that sialic acid itself is directly involved in cell-cell adhesion. We suggest that aberrant O-glycosylation in carcinoma cells inhibits stable expression of dysadherin and leads to the up-regulation of E-cadherin expression by an unknown mechanism, resulting in increased cell-cell adhesion. The carbohydrate-directed approach to the regulation of dysadherin expression might be a new strategy for cancer therapy.
KW - Benzyl-α-Ga1NAc
KW - Cell-cell adhesion
KW - Dysadherin
KW - E-cadherin
KW - O-glycosylation
UR - http://www.scopus.com/inward/record.url?scp=0037481949&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037481949&partnerID=8YFLogxK
U2 - 10.1093/glycob/cwg065
DO - 10.1093/glycob/cwg065
M3 - Article
C2 - 12672699
AN - SCOPUS:0037481949
VL - 13
SP - 521
EP - 527
JO - Glycobiology
JF - Glycobiology
SN - 0959-6658
IS - 7
ER -